Finding the Third Proportional to 215,820 and 338,558.50

Step by Step Solution

1. Step 1: Write the proportion equation
   215,820 : 338,558.50 = 338,558.50 : x
2. Step 2: Convert to fraction form
   215,820/338,558.50 = 338,558.50/x
3. Step 3: Cross multiply
   215,820x = 338,558.50 × 338,558.50
4. Step 4: Simplify right side
   215,820x = 114,621,857,922.25
5. Step 5: Solve for x
   x = 114,621,857,922.25/215,820
6. Step 6: Final answer
   x = 531,099.33